# A118204 (b-file synthesized from sequence entry) 1 1 2 1 3 2 4 3 5 24 6 60 7 720 8 42 9 8064 10 60480 11 3628800 12 2851200 13 95800320 14 1556755200 15 29059430400 16 653837184000 17 20922789888000 18 59281238016000 19 6402373705728000 20 3379030566912000 21 62382102773760000 22 91233825306624000